1. Field of the Invention
The present invention relates generally to a gardening implement, and more particularly to a tree pruner.
2. Description of Related Art
As shown in FIG. 1, a tree pruner of the prior art comprises a fixation seat 10 and a link rod 30. The fixation seat 10 is provided at the bottom end with a connection portion 11 which is fastened with a rod 20, and is provided with a first pulley set 12. The fixation seat 10 is provided at the top end with a hook 13 and a blade 14 pivoted thereto. The hook 13 is connected at the top end with one end of a tension spring 15. The link rod 30 is pivoted at the bottom end with the fixation seat 10 and the blade 14 and is provided with a second pulley set 31. A pull cord 32 runs through the first pulley set 12 and the second pulley set 31. The link rod 30 is connected at the top end with the top end of the tension spring 15. In operation, the pull cord 32 is pulled to actuate the link rod 30 to turn on a pivot 33 on which the blade 14 is pivotally mounted. As the link rod 30 is actuated to turn, the blade 14 works to sever a tree twig in conjunction with the hook 13. The application arm between the pivot 33 and the second pulley set 31 is relatively long and is devoid of any reinforcing structure, thereby undermining the overall efficiency of the prior art tree pruner. In other words, the user of the prior art tree pruner often fails to sever the tree twig in one try. When the pull cord 32 is pulled for the second time in an effort to sever the tree twig, the action stroke of the second application is lengthened in view of the recovery action of the tension spring 15 on the link rod 30, thereby resulting in the disengagement of the blade 14 from the tree twig.
The primary objective of the present invention is to provide a tree pruner which is free of the deficiencies of the prior art tree pruner described above.
In keeping with the principle of the present invention, the foregoing objective of the present invention is attained by a tree pruner comprising a fixation seat, a cutter, a link rod, and an auxiliary rod member. The auxiliary rod member is formed of a support rod and an expandable push rod. The support rod is pivoted at one end with the link rod, and at the other end with an extension arm of the cutter. The expandable push rod is pivoted at one end with the link rod, and at the other end with the support rod. The auxiliary rod member serves to enhance the structural rigidity of the link rod, so as to improve the efficiency of the tree pruner.
The features and the advantages of the present invention will be more readily understood upon a thoughtful deliberation of the following detailed description of a preferred embodiment of the present invention with reference to the accompanying drawings.